Cab for an agricultural working vehicle

ABSTRACT

A cab for an agricultural working vehicle has a cab base and a cab roof, between which a windshield and side windows are situated in a frame structure, and a driver&#39;s seat situated on the cab base. There is at least one air treatment device for cooling and heating an inlet air flow which is supplied to the cab through an intake duct. The air treatment device has at least one first air distribution duct having at least one first air outlet opening, and at least one second air distribution duct having at least one second air outlet opening. The first air outlet opening outputs a first air flow substantially along the windshield and the second air outlet opening outputs a second air flow directed in the direction of the driver&#39;s seat. The first air flow has a higher temperature than the second air flow.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 USC 119 of German Application No. 10 2017 115 124.9, filed on Jul. 6, 2017, the disclosure of which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a cab for an agricultural working vehicle comprising a cab base and a cab roof, between which a windshield and side windows are situated, being accommodated by a frame structure, and a driver's seat situated on the cab base. There is at least one air treatment device for cooling and heating an inlet air flow which can be supplied to the cab, by means of at least one fan, through an intake duct situated in the area of the cab roof, and at least one first air distribution duct in the area of the cab roof comprising at least one first air outlet opening which opens into the interior space of the cab

Cabs for an agricultural working vehicle of the type used in agriculture, forestry, or the construction industry, are a full-fledged workplace which is often utilized by an operator during an entire working day. Examples thereof are tractors, self-propelled harvesting machines such as combine harvesters or forage harvesters, wood harvesting machines, or wheeled loaders. Since such working vehicles are utilized in highly diverse climatic environmental conditions, the cabs are equipped with an air treatment device which is used for cooling and heating a fresh-air flow supplied to the cab.

A cab for a working vehicle of this type is known from EP 2 080 649 B1. The cab comprises a base and a cab roof, between which a windshield and side windows are situated, which are accommodated by a frame structure and provide an all-around view for the operator. A driver's seat is situated on the base of the cab. Situated in the cab roof of the cab is an air treatment device for cooling and heating a fresh-air flow which can be supplied from outside the cab through an intake duct situated in the cab roof by means of at least one fan. An air flow which has been treated by the air treatment device is fed to first air outlet openings which open into the interior space of the cab through at least one first air distribution duct in the cab roof. In this case, in the cab according to EP 2 080 649 B1, a plurality of air guide ducts for the air to be blown in is formed in the cab roof, base, and side areas of the cab and assigned to which are the air outlet openings directed into the interior space of the vehicle cab. Each of the air supply ducts is provided with a fan, in order to maintain a constant temperature in the different areas of the cab, inter alia, in the foot area and head area of an operator, by means of a suitable control of the fan. The air guide ducts provided in the frame structure, in particular, i.e., the so-called A-pillars and B-pillars, have the disadvantage that the flow resistances are relatively high due to the small cross-section of the frame structure.

SUMMARY OF THE INVENTION

Against this background, the problem addressed by the present invention is that of refining a cab of the type mentioned at the outset, in order to achieve an improvement on the sense of comfort.

This problem is solved according to the invention by a cab for an agricultural working vehicle which comprises a base and a cab roof, between which a windshield and side windows are situated, being accommodated by a frame structure, and a driver's seat situated on the base. The cab also comprises at least one air treatment device for cooling and heating an inlet air flow which can be supplied to the cab, by means of at least one fan, through an intake duct situated in the area of the cab roof, and at least one first air distribution duct in the area of the cab roof comprising at least one first air outlet opening which opens into the interior space of the cab. The air inlet flow is composed of fresh air supplied from the outside and air circulating in the cab having variable volumetric flow portions, wherein a volumetric flow portion can also tend to approach zero. In order to increase comfort, at least one second air distribution duct in the area of the cab roof is provided with at least one second air outlet opening which opens into the interior space of the cab, wherein the at least one first air outlet opening is positioned in the area of the windshield and outputs a first air flow substantially along the windshield, directed downward, and the at least one second air outlet opening, which opens into the interior space of the cab, outputs a second air flow directed in the direction of the driver's seat. The first air flow has a higher temperature than the second air flow. In contrast to the cab known from the related art, a cab designed in this way has the advantage that a temperature stratification in the interior of the cab can be achieved. While the warmer first air flow flows substantially along the windshield into the foot area of an operator, the colder second air flow is supplied in the head area of the operator. This contributes to a better interior climate, since the temperature perceived by the operator in the head and foot areas is more constant due to this temperature stratification.

Yet another advantage is that air outlet openings situated in the frame structure of the cab and air distribution ducts located in the frame structure can be dispensed with, since the first air flow is guided downward, substantially along the windshield. The at least one first and second air outlet openings are arranged in the area of the cab roof. The at least one first and second air distribution ducts can be arranged in the cab roof in this case. They can also be arranged in the roof liner or between the cab roof and the roof liner. A design of the at least one first and second air distribution ducts as separate components is also conceivable. This also has the advantage that the A-pillars and the B-pillars of the cab, in particular, can be narrowly dimensioned, in order to ensure good visibility. Dispensing with air outlet openings in the A- and B-pillars also results in a simplification of the production of the pillars.

One advantageous refinement provides that the air treatment device comprises a separate cooling device and heating device, wherein the inlet air flow, in particular a mixture of fresh air and circulating air having different volumetric flow portions, is initially fed to the cooling device which outputs the treated air flow to the downstream heating device. In this case, it can be provided that the flow through the heating device is prevented by at least one closure flap. In this way, the air flow can be guided past the heating device by means of the at least one closure flap. Due to such a measure, a smaller dimensioning of the cooling device can be achieved, since the permanent heating of the air flow emerging from the cooling device is at least reduced. This is advantageous when the working vehicle is operated at high outside temperatures. The installation of heat-insulating closure flaps is advantageous in this context.

In this case, air treated by the heating device can be introduced into the at least one first air distribution duct, while air treated by the cooling device can be proportionally branched off into or mixed into the at least one second air distribution duct.

In particular, a bypass can be situated in the at least one first air distribution duct, by means of which the first air flow from the first air distribution duct can be proportionally fed to the at least one second air distribution duct. As a result, a thorough mixing of the warmer first air flow with the cooler second air flow can be achieved before this air flow is conducted into the interior of the cab through the at least one second air outlet opening.

To this end, the volumetric flow of the first air flow fed to the at least one second air distribution duct through the bypass can be limitable by at least one flow-limiting element. In the simplest case, an orifice plate or a restrictor is provided as the flow-limiting element.

One preferred refinement provides that the flow-limiting element can be adjusted depending on temperature and/or volume. To this end, the cross-section of the at least one passage opening of the flow-limiting element can taper in the direction of flow. In this way, a temperature control can be provided, in order to vary the temperature of the second air flow emerging from the at least one second air outlet opening.

Moreover, it can be provided that the volumetric flow of the first air flow supplied via the bypass can be limited by at least one adjustable flap. The flap can be actuatable via an actuator system, for example, an electric servomotor. The flap can be transferred into different positions by means of the actuator system, and therefore the volumetric flow portion of the first air flow, which is branched off via the first bypass, can be varied. The adjustment can take place in discrete steps or steplessly. According to one refinement, the control of the actuator system can be coupled to a temperature sensor, thereby resulting in a temperature-dependent volumetric flow control.

It is advantageous when the heating device is inclined relative to the horizontal. The inclined arrangement of the heating device contributes to the compliance with the overall height. Due to the limited installation space available in the cab roof of the cab, the distance between the cooling device and the heating device is low. As a result, the area of the mixing of the first air flow and the second air flow is also limited. The flap of the bypass is designed to be fluidically optimized in order to improve the mixing of the first air flow and the second air flow. In this case, straight edges on the flap are essentially dispensed with, and therefore not only better mixing, but also a quieter operation can be achieved. In addition, rib-shaped elements, which facilitate the mixing, can be situated in the area of the mixing.

In particular, the first air distribution duct situated adjacent to the windshield should extend substantially across the width of the cab. Particularly preferably, at least two first air outlet openings in the cab roof are situated in the area of the windshield. In addition, at least one first air outlet opening in the cab roof is situated in parallel to each of the side windows. The curtain-like air flow emerging from the first air outlet openings is utilized for clearing fogged or iced windshields as quickly as possible, in order to ensure safe guidance of the agricultural working vehicle by way of appropriately good all-around visibility.

Preferably, means which influence the first air flow can be provided in the first air distribution duct. The means are utilized for equalizing the volumetric flow of the first air flow flowing out through at least two first air outlet openings. Due to an arrangement of the intake duct in the edge area of the cab roof generally on one side, the distribution of the supplied inlet air flow in the air treatment device is non-uniform. This continues up to the first air outlet openings. In particular, when two adjacently situated fans or two fan rotors are utilized, this non-uniform distribution results in a temperature difference between the partial inlet air flows output by the fans to the air treatment device. A nearly uniform distribution is achieved by way of a fluidic influencing of the inlet air flow fed to the two fans. Due to the means which influence the first air flow, a more homogeneous air distribution in the cab is achieved.

To this end, the means can be designed as ribs, baffles, duct sections having changed cross-sections, or guide walls. These means are preferably symmetrically situated in the first air distribution duct.

In addition, at least one air filter in the intake duct can be situated in the cab roof. The air filter can be removed through a closeable opening on the outer side of the cab roof, and therefore, in the removed state, a circulating air filter positioned behind the air filter can be removed through the same opening. In addition to the supply of fresh air, circulating air which has been treated together with the air treatment device is supplied to the cab with the inlet air flow. Therefore, a circulating air filter is utilized in addition to an air filter which is used for filtering the supplied fresh air. Due to the fact that the circulating air filter can be removed through the same opening in the cab roof as the air filter, it is emptied toward the outside when removed. Installation preferably takes place horizontally, i.e., the inlet opening of the circulating air filter is oriented substantially perpendicularly to the direction of removal. This has the advantage that residue remaining in the circulating air filter when it is removed cannot enter the interior of the cab roof.

One embodiment provides that the interior of the cab can be fluidically connected to the intake duct via a vent flap which can be actuated on one side. An overpressure building up in the cab, which is caused by the cab door being shut, can be compensated for by means of the vent flap. The air compressed by the abruptly built-up overpressure can escape, as an air burst, through the vent flap. The air filter situated in the intake duct, and the circulating air filter, can be set into vibration by means of the air burst, and therefore particles adhering on the filter surfaces become detached. The vent flap is arranged in the area above the cab door in this case.

In addition, the interior of the cab can be fluidically permanently connected to the surroundings via a ventilation duct, wherein the ventilation duct comprises a section having a substantially U-shaped course. The section of the ventilation duct can function according to the operating principle of a siphon.

The ventilation of the cab is subdivided into two separate subsystems. The first subsystem comprises the vent flap which can be actuated on one side and which can be fluidically connected to the intake duct. The second subsystem comprises the ventilation duct which permanently connects the interior of the cab to the surroundings.

The problem mentioned at the outset is also solved by an agricultural working vehicle comprising a cab as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in greater detail in the following with reference to one exemplary embodiment represented in the drawings.

In the drawings:

FIG. 1 shows a working vehicle designed as an agricultural tractor;

FIG. 2 shows a view of a cab roof of a working vehicle from below;

FIG. 3 shows a longitudinal sectional view along the line A-A according to FIG. 2 of the cab roof;

FIG. 4 shows a partial view X according to FIG. 2 of a lower shell;

FIG. 5 shows a perspective view of a section B according to FIG. 2 of the cab roof;

FIG. 6 shows a partial sectional view of the cab roof along the line E-E according to FIG. 2 including an accommodating section for an air filter;

FIG. 7 shows a perspective view of a cover element closing the accommodating section;

FIG. 8 shows a partial view of the cab roof obliquely from the rear, including a filter tube to be installed;

FIG. 9 shows a partial view of the cab roof 23 obliquely from the rear with the filter tube installed;

FIG. 10 shows a perspective partial view D according to FIG. 2 of the cab roof obliquely from the rear, including a wall insert;

FIG. 11 shows a perspective partial view D according to FIG. 2 of the cab roof obliquely from the rear, including a wall insert according to yet another embodiment;

FIG. 12 shows a perspective partial view of the cab roof obliquely from below;

FIG. 13 shows a partial view of the cab roof in the longitudinal section along the line E-E according to FIG. 2;

FIG. 14 shows a perspective partial view of the cab roof from the side;

FIG. 15 shows a perspective view of the cab obliquely from below; and

FIG. 16 shows a perspective partial view of the lower shell from above.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows a working vehicle which is designed as an agricultural tractor 1 and is formed in monobloc design. In this case, an engine housing 2 of an internal combustion engine of the tractor 1 is connected to a transmission and rear axle housing 3. In its front area, the tractor 1 comprises a front axle 4 which is fastened to the engine housing 2 via a front axle housing which is not represented in greater detail. In the rear area of the tractor 1, two wheel axles extend away from the transmission and rear axle housing 3, only one wheel axle 5 of which is visible in the representation according to FIG. 1. The wheel axles drive rear wheels 6 which are covered over a portion of their outer circumference by fenders 7 and 8 on both sides of the tractor 1, wherein the fenders 7 and 8 can be integrally formed with an operator's platform 9. Situated on this operator's platform 9, which is integrally formed with the fenders 7 and 8, are, inter alia, a driver's seat 10, a steering device 11, and a display and control unit 12. It lies within the scope of the invention that the working vehicle can also be a self-propelled combine harvester or forage harvester, as well as any other type of agricultural, forestry, or municipal commercial vehicle comprising a cab.

A driver's cab 13 of the tractor 1 forms, with the operator's platform 9, a unit which is mounted in a resilient and vibration-damping manner with respect to the transmission and rear axle housing 3 supporting this unit, via elements which are not represented in greater detail. Therefore, a cab base 14 is formed by the operator's platform 9, and lower frame parts 15 of the driver's cab 13 partially surround the cab base 14 and are guided in other areas above the fenders 7 and 8. Extending away from the lower frame parts 15, in the front area of the driver's cab 13, are substantially vertically extending A-pillars 16 and 17, spaced apart from which B-pillars 18 and 19 and, finally, at the rear of the driver's cab 13, rear pillars 20 and 21 extend.

The pillars 16 to 21 are connected to each other at their upper ends via upper frame parts 22, wherein these upper frame parts 22 are circumferentially formed and accommodate a cab roof 23 designed as a prefabricated module. As is also shown in FIG. 1, the driver's cab 13 is glazed all-around, i.e., the driver's cab comprises a windshield 24 and front windshield parts 25 which are separated from the windshield by transverse frames and are located in the footwell. In addition, a glazed cab door 26 and 27 is provided on each of the two sides of the driver's cab 1, as shown in the perspective representation, each of which is pivotably mounted on the B-pillar 18 and 19, respectively, and abuts the A-pillar 16 and 17, respectively. Located behind the glazed cab doors 26 and 27 are side windows 28 and 29 which are located between the B-pillar 18 and 19, respectively, and the corresponding rear pillar 20 and 21, respectively. Finally, the driver's cab 13 is closed on its rear side, i.e., in the area located between the rear pillars 20 and 21, by a rear window 30 which can extend up to the cab base 14 in order to improve the view of working devices mounted in the rear area of the cab 13.

FIG. 2 shows the cab roof 23 in a view from below, wherein an upper shell 32 limiting the cab roof 23 is represented transparently for the sake of improved clarity.

In FIG. 3, a longitudinal sectional view of the cab roof 23 along the line A-A according to FIG. 2 is represented. The cab roof 23 comprises at least two shells, i.e., an upper shell 31 and a lower shell 32. In the exemplary embodiment represented, an air treatment device 33 is situated between the upper shell 31 and the lower shell 32. An arrangement of an air treatment device deviating therefrom is conceivable, for example, in the area outside the cab roof 23. The air treatment device 33 comprises at least one fan 34 a and 34 b, a cooling device 35, and a heating device 36. Preferably, two fans 34 a, 34 b are provided, which feed an inlet air flow ZF to the cooling device 35. FIG. 3 shows a view of the cab roof 23 from above, wherein the upper shell 31 is transparently represented. The inlet air flow ZL is drawn through an intake duct 46 and is fed to the fans 34 a, 34 b, as indicated in FIG. 3. The inlet air flow ZL flows through the cooling device 35 and subsequently reaches the heating device 36 which is spaced apart from the cooling device. A first bypass 42 is situated between the cooling device 35 and the heating device 36. The bypass 42 comprises a flow-limiting element designed as a flap 43. In a simpler embodiment of the first bypass 42, the volumetric flow of cooled inlet air to be branched off can be limited by at least one flow-limiting element which is designed as a restrictor or a throttle. The volumetric flow of cooled inlet air that is not branched off by the first bypass 42 flows through the heating device 36. Disposed downstream from the heating device 36 is a second bypass 44. The second bypass 44 is designed as a flap 45. The volumetric flow which emerges from the heating device 36 and is guided past the second bypass 44 forms a first air flow 47 which is fed to a first air distribution duct 37. The first air distribution duct 37 has a substantially U-shaped course. In this case, approximately parallel subsections of the first air distribution duct 37 extend at least in sections in the longitudinal direction of the cab 13 between the particular A-pillar 16 and 17 and the particular B-pillar 18 and 19, respectively, or the corresponding rear pillar 20 or 21, respectively. A transversely extending subsection of the first air distribution duct 37 extends substantially across the width of the cab 13 in the area of the windshield 24. The first air distribution duct 37 comprises first air outlet openings 38. The first air flow 47, which is directed downward and flows substantially along the windshield 24, emerges from the first air outlet openings 38.

The partial volumetric flow, which has branched off downstream from the cooling device 35 via the first bypass 42, circumvents the heating device 36 and enters a mixing zone 41 located downstream from the heating device 35. A partial volumetric flow of the inlet air flow ZL heated by the heating device 36, which has been branched off by the second bypass 44, is introduced into this mixing zone 41. The two partial volumetric flows form a second air flow 48 which is fed to a second air distribution duct 39. The second air distribution duct 39 comprises second air outlet openings 40 which open into the interior of the cab 13. The second air flow 48, which is directed in the direction of the driver's seat 10, emerges from the second air outlet openings 40.

There is a temperature difference between the first air flow 47 and the second air flow 48, wherein the first air flow 47 has a higher temperature than the second air flow 48. This has the effect that the second air flow 48 can be utilized, on the one hand, for defrosting at least the windshield 24 as well as for supplying warm air in the area of the cab base 14 than in the area of the driver's seat 10, which is located higher up. Preferably, the temperature difference between the second air flow 48 when emerging from the second air outlet openings and the first air flow 47 when reaching the cab base 14 lies in a range which is generally perceptible by an operator without technical auxiliary means. In this way, a temperature distribution in the cab 13 is achieved, which is perceived by an operator as being particularly comfortable. Both the flap 43 and the flap 45 can be controlled in a temperature-dependent manner, for example, in order to change the branched-off partial volumetric flows which are combined to form the second air flow 48.

The inlet air flow ZF is drawn in through the intake duct 46 by the fans 34 a, 34 b and is fed to at least one filter element designed as an air filter 49, as represented in FIG. 2. The air filter or filters 49 is/are situated in the accommodating sections 50 in the cab roof 23. The air filters 49 are designed as pocket filters. Instead of the pocket filters, category 4 filter elements can also be inserted into the accommodating sections 50; such filters must be utilized when pesticides, for example, are to be applied by the working vehicle 1. A circulating air filter 51 is situated so as to lie substantially transversely to the windshield 25. The circulating air filter 51 filters air drawn out of the cab 13 before this air is returned to the air treatment device 33 as circulating air.

A vent flap 52 is situated adjacent to the intake duct 46 and fluidically connects the interior of the cab 13 to the intake duct 46. The vent flap 52 can be actuated on only one side and opens when an overpressure abruptly occurs in the interior of the cab 13, which is induced by the cab door 26 being closed. The air flow escaping through the vent flap 52 travels through the intake duct 46 and reaches the air filters 49. The abruptly occurring air pressure difference sets the air filters 49 into motion or vibration. In this way, a cleaning effect can be achieved, in that particles that have deposited on the walls of the air filter 49 are detached by way of the motion. The intake duct 46 is simultaneously utilized for ventilation.

The representation in FIG. 2 also shows that the upper shell 31, opposite the transparently represented lower shell 32, comprises, on one side, a flat overhang 74 extending across the width of the cab roof 23. The overhang 74 bears, opposite the lower shell 32, on the lower shell by means of at least two profiled elements 73 which are spaced apart from each other. The profiled elements 73 are designed to be substantially tetrahedral or as 3D ribs in order to reduce the weight while simultaneously maintaining or improving the stability.

Since the inlet air flow ZL is drawn in on only one side, a greater proportion of cold inlet air is fed by the fan 34 a, which is situated closer to the intake duct 46, than by the fan 34 b which is spaced farther away from the intake duct 46. In order to achieve a homogeneous distribution of the first air flow 47 flowing out of the first air outlet openings 38, means are provided, at least in the first air distribution duct 37, for fluidically influencing the first air flow 47, which is represented in FIGS. 4 and 5. In this case, the representation in FIG. 4 shows a detailed view X according to FIG. 2. A section B according to FIG. 2 is represented in FIG. 5. The means are ribs 53, baffles 54, angles of the baffles 54 or the side walls of the first air distribution duct 37, or any other components influencing the flow behavior, such as a partially open housing 55 which surrounds the first air outlet opening 38 in sections. A variation of individual cross sections of the first air distribution duct 37 is also significant in terms of influencing the flow.

FIG. 6 shows a partial sectional view of the cab roof 23 along the line C-C according to FIG. 2, which shows the accommodating section 50 for one of the air filters 49. The accommodating section 50 extends substantially horizontally between the upper shell 31 and the lower shell 32.

FIG. 7 shows a cover element 56 which closes the accommodating section 50. The cover element 56 is detachably situated on a circumferential side wall 57 formed between the upper shell 31 and the lower shell 32. In the mounted position, the cover element 56 closes so as to be flush with the circumferential side wall 57. The cover element 56 comprises fastening sections 59 in order to be fastened on the upper shell 31, the fastening sections allowing the cover element 56 to pivot upward in the direction of the upper shell 31. Fastening elements 60 are provided for the detachable connection of the cover element 56 to the lower shell 32. The cover element 56 comprises, on its inner side, at least two pair of webs 58 a, 58 b which extend, in sections, in the direction of the accommodating section 50. The webs 58 a, 58 b of one pair have different lengths, which is due to the outwardly curved contour of the cover element 56. The length of the webs 58 a, 58 b is sized in such a way that, when an air filter 49 is installed in the accommodating section 50, the webs 58 a, 58 b bear on the frame of the air filter 49 and fix the air filter in the accommodating section 50, wherein the cover element 56 simultaneously closes flush with the circumferential side wall 57. If the filter element 49 were not correctly inserted into the accommodating section 50, the cover element 56 would not be able to close flush with the circumferential side wall 57.

A partial view of the cab roof 23 obliquely from the rear is represented in FIGS. 8 and 9. A roof side element 61 is pivotably articulated on the circumferential side wall 57 and can be transferred out of a position which is substantially parallel to the upper shell 31 into a position which is slanted at an angle with respect to the upper shell 31. The latter slanted position of the roof side element 61 is represented in FIG. 8. On the back side of the cab roof 23, the circumferential side wall 57 comprises a section 62 including air supply openings 62 a which are adjoined by the intake duct 46. An accommodating element 63 which is designed open toward the top side of the cab roof 23 is situated at the section 62. A flange-shaped connecting element 64, which is situated on a tubular filter element 65, at the end thereof, can be inserted into the accommodating element 63 from above in a form-fit manner. The tubular filter element 65 situated on the outside of the cab 13 is used for the pre-filtration of large pieces of debris out of the air that is drawn in, whereby the useful life of the air filter 49 is extended. To this end, the form-fit connection between the accommodating element 63 and the connecting element 64 is designed as a dovetail joint. In order to connect or disconnect the tubular filter element 65, the operator need only swivel the roof side element 61 upward. Subsequently, the operator can insert or slide the connecting element 64 in the vertical direction into the accommodating element 63. When the roof side element 61 is swiveled downward and the tubular filter element 65 is installed, the connecting element 64 is prevented from sliding out of the accommodating element 63.

FIGS. 10 and 11 show a perspective partial view D according to FIG. 2 of the cab roof 23 from the rear. A recess 66 is situated in the circumferential side wall 57. The recess 66 is uniformly sized for cab roofs 23 or cabs 13 which are to be utilized for different working vehicles 1, such as tractors, self-propelled combine harvesters, or forage harvesters. A wall insert 67, which is provided with at least one passage opening 68, is inserted into the recess 66 and closes the recess 66. FIG. 10 shows a first embodiment of the wall insert 67 comprising multiple passage openings 68. FIG. 11 shows a second embodiment of the wall insert 67 comprising only one passage opening 68. The number and the configuration of the passage openings 68 of the particular wall insert 67 depend on the particular type of working vehicle 1.

A perspective partial view of the cab roof 23 from below is represented in FIG. 12. Multiple hollow-cylindrical sections 69 comprising a closed lateral surface are situated between the lower shell 32 and the upper shell 31. The hollow-cylindrical sections 69 can have cross-sectional shapes which are identical or which differ from each other. A base surface 70 of the particular hollow-cylindrical section 69, which is designed to be open and which opens into the lower shell 32, can be sealingly closed by means of a loudspeaker diaphragm. The hollow-cylindrical sections 69, each of which is closed by the loudspeaker diaphragm, form a resonance body. The volumes of the hollow-cylindrical sections 69 can each be changed by volume-limiting elements. In addition, the representation in FIG. 12 shows that the interior of the cab 13 is fluidically permanently connected to the surroundings by means of a ventilation duct 71 situated in the cab roof 23. The ventilation duct 71 comprises a section 72 having a substantially U-shaped course, which is represented in greater detail in FIG. 13 in the partial view of the cab roof 23 in the longitudinal section along the line E-E according to FIG. 2.

The representation in FIG. 14 shows a perspective partial view of the cab roof 23 from the side. The accommodating sections 50 are represented without air filters 49 inserted. The circulating air filter 51 can be pulled outward through the exposed front accommodating section 50. This arrangement has the advantage that the circulating air filter 51 need not be emptied inwardly, into the cab, as is common in the related art, but rather outwardly. Due to the removal of the horizontally situated circulating air filter 51 toward the outside, the situation is avoided in which particles taken up by the filter trickle out.

An additional fan 75 is situated adjacent to the fans 34 a and 34 b. The additional fan 75 is used for compensating for the increased demand for inlet air during a replacement of the air filters 49, which are designed as pocket filters, by filter elements, for example of category 4 or lower, which are accommodated by the accommodating sections 50 and are fixed by the cover element 56 in the same way. To this end, the different filter elements are designed as modules which are adapted to the accommodating sections 50, and therefore ease of replacement is ensured.

A perspective view of the cab 13 obliquely from below is represented in FIG. 15. The cab roof 23 is designed as a prefabricated module which can be mounted on the frame structure of the cab 13. To this end, the upper, circumferentially designed frame parts 22 comprise multiple fastening points 76, onto which the preassembled cab roof 23 can be placed. “Preassembled” and “prefabricated” mean that all components necessary for the operation of the air treatment device 33 have been situated between the upper shell 32 and the lower shell 33 in an upstream production step. The lower shell 33 is covered by a roof liner situated thereon.

As is clear from FIG. 15 in particular, the first air outlet openings 38 and the second air outlet openings 40 are installed exclusively in the cab roof 23. In this case, multiple first air outlet openings 38 are situated next to each other in the area of the windshield 24. The air inlet openings discharge the first air flow 47 which is directed from top to bottom and flows substantially along the windshield 24 to the cab base 14, i.e., into the foot area of the operator. The second air outlet openings 40 situated above the driver's seat 10 discharge the second air flow 48 which is directed onto the head area of the operator. As described above, there is a temperature difference between the warmer first air flow 47 and the cooler second air flow 48, which can be perceived by the operator without auxiliary means, in order to achieve a temperature distribution or temperature stratification which is perceived by the operator as being pleasant.

In order to influence the temperature distribution, the addition of inlet air cooled by the cooling device 35 can be controlled by means of the flap 43. The flap 43 can be adjusted by means of a servomotor which, in turn, can be controlled by an additional temperature sensor.

Situated in the lower shell or the upper shell of the cab roof is at least one guide groove 81 which is used for the form-fit accommodation, in sections, of at least one tube 80 for discharging condensate. The at least one guide groove 81 makes it possible to guide the tube, which opens into an A-pillar 17 of the frame structure, in a kink- and compression-free manner, in particular in the transition area from the cab roof into the A-pillar 17. The preassembly is facilitated in this way, wherein, during the installation of the prefabricated cab roof 23 on the frame structure, the guide groove 81 prevents the tube 80 from kinking during connection to the A-pillar 17, which at least limits a discharge of the condensate.

A perspective partial view of the lower shell 32 from above is represented in FIG. 16. The air treatment device 33 comprises at least one connector 77 which is connected to a corresponding mating connector 78. The mating connector 78 feeds a cooled air flow to a roof cooling compartment 76 integrated into the cab roof 23. The connector 77 as well as the mating connector 78 comprise slanted contact surfaces 77 a, 78 a, respectively. The contact surfaces 77 a and 78 a are designed to be complementary to each other, and therefore the insertion of the air treatment device 33 simultaneously results in a sealing connection of the at least one connector 77 to the mating connector 78. The air treatment device 33 can also be designed to include slanted contact surfaces in the area of the first air distribution duct 37, and therefore a sealing can be achieved here as well during the installation of the air treatment device 33.

LIST OF REFERENCE SIGNS

-   1 tractor -   2 engine housing -   3 transmission and rear axle housing -   4 front axle -   5 wheel axle -   6 rear wheel -   7 fender -   8 fender -   9 operator's platform -   10 driver's seat -   11 steering device -   12 control unit -   13 driver's cab -   14 cab base -   15 frame part -   16 A-pillar -   17 A-pillar -   18 B-pillar -   19 B-pillar -   20 rear column -   21 rear column -   22 frame part -   23 cab roof -   24 windshield -   25 windshield part -   26 cab door -   27 cab door -   28 side window -   29 side window -   30 rear window -   31 upper shell -   32 lower shell -   33 air treatment device -   34 a fan -   34 b fan -   35 cooling device -   36 heating device -   37 first air distribution duct -   38 first air outlet opening -   39 second air distribution duct -   40 second air outlet opening -   41 mixing zone -   42 first bypass -   43 flap -   44 second bypass -   45 flap -   46 intake duct -   47 first air flow -   48 second air flow -   49 air filter -   50 accommodating section -   51 circulating air filter -   52 ventilation flap -   53 rib -   54 baffle -   55 housing -   56 cover element -   57 side wall -   58 a web -   58 b web -   59 fastening section -   60 fastening element -   61 roof side element -   62 section -   62 a air supply openings -   63 accommodating element -   64 connecting element -   65 tubular filter element -   66 recess -   67 wall insert -   68 passage opening -   69 hollow-cylindrical section -   70 base surface of 69 -   71 ventilation duct -   72 U-shaped section -   73 profiled element -   74 overhang -   75 additional fan -   76 fastening point -   77 roof cooling compartment -   78 connector -   78 a contact surface -   79 mating connector -   79 a contact surface -   80 tube -   81 guide groove -   ZL inlet air 

What is claimed is:
 1. A cab for an agricultural working vehicle, comprising: a cab base; a cab roof; a windshield and side window situated between the cab base and cab roof, a frame structure accommodating the windshield and side window; a driver's seat situated on the cab base; at least one air treatment device for cooling and heating an inlet air flow (ZL) supplied to the cab through at least one fan and an intake duct situated in an area of the cab roof, the air treatment device comprising: at least one first air distribution duct in the area of the cab roof, having at least one first air outlet opening which opens into an interior space of the cab; and at least one second air distribution duct in the area of the cab roof having at least one second air outlet opening which opens into the interior space of the cab; wherein the at least one first air outlet opening is positioned in an area of the windshield and outputs a first air flow substantially along the windshield, directed downward, and the at least one second air outlet opening outputs a second air flow directed in a direction of the driver's seat, wherein the first air flow has a higher temperature than the second air flow, wherein the air treatment device comprises a separate cooling device and downstream heating device, wherein the cooling device is configured to initially receive inlet air flow and output a treated air flow, at least proportionally, to the downstream heating device, and wherein the first air distribution duct is configured to receive air treated by the heating device, while the second air distribution duct is configured to receive a proportional amount of branched off air treated by the cooling device.
 2. The cab as claimed in claim 1, wherein the heating device is inclined relative to horizontal.
 3. The cab as claimed in claim 1, wherein the first air distribution duct is situated adjacent to the windshield and extends substantially across a width of the cab.
 4. The cab as claimed in claim 1, further comprising at least one air filter in the intake duct and situated in the cab roof, said air filter being removable through a closeable opening on an outer side of the cab such that when said air filter in the intake duct is removed a circulating air filter positioned behind the air filter in the intake duct can be removed through the same opening.
 5. The cab as claimed in claim 1, further comprising a vent flap that is configured to be actuated on one side and enables a fluidic connection between the interior of the cab and the intake duct.
 6. The cab as claimed in claim 1, further comprising a ventilation duct having a substantially U-shaped course, the ventilation duct being configured for fluidically permanently connecting the interior of the cap to the surroundings.
 7. An agricultural working vehicle comprising a cab as claimed in claim
 1. 8. A cab for an agricultural working vehicle, comprising: a cab base; a cab roof; a windshield and side window situated between the cab base and cab roof, a frame structure accommodating the windshield and side window; a driver's seat situated on the cab base; at least one air treatment device for cooling and heating an inlet air flow (ZL) supplied to the cab through at least one fan and an intake duct situated in an area of the cab roof, the air treatment device comprising: at least one first air distribution duct in the area of the cab roof, having at least one first air outlet opening which opens into an interior space of the cab; and at least one second air distribution duct in the area of the cab roof having at least one second air outlet opening which opens into the interior space of the cab; wherein the at least one first air outlet opening is positioned in an area of the windshield and outputs a first air flow substantially along the windshield, directed downward, and the at least one second air outlet opening outputs a second air flow directed in a direction of the driver's seat, wherein the first air flow has a higher temperature than the second air flow, and wherein a bypass is situated in the at least one first air distribution duct, by means of which the first air flow from the first air distribution duct is proportionally fed to the at least one second air distribution duct.
 9. The cab as claimed in claim 8, further comprising a flow-limiting element that is configured to limit a volumetric flow of the first air flow fed through the bypass.
 10. The cab as claimed in claim 9, wherein the flow-limiting element is configured to be adjusted depending on temperature and/or volume.
 11. The cab as claimed in claim 8, further comprising at least one adjustable flap that is configured for limiting a volumetric flow of the first air flow fed through the bypass.
 12. A cab for an agricultural working vehicle, comprising: a cab base; a cab roof; a windshield and side window situated between the cab base and cab roof, a frame structure accommodating the windshield and side window; a driver's seat situated on the cab base; at least one air treatment device for cooling and heating an inlet air flow (ZL) supplied to the cab through at least one fan and an intake duct situated in an area of the cab roof, the air treatment device comprising: at least one first air distribution duct in the area of the cab roof, having at least one first air outlet opening which opens into an interior space of the cab; and at least one second air distribution duct in the area of the cab roof having at least one second air outlet opening which opens into the interior space of the cab; wherein the at least one first air outlet opening is positioned in an area of the windshield and outputs a first air flow substantially along the windshield, directed downward, and the at least one second air outlet opening outputs a second air flow directed in a direction of the driver's seat, wherein the first air flow has a higher temperature than the second air flow, wherein there are at least two first air outlet openings, and further comprising components which influence the first air flow provided in the first air distribution duct, said components being configured for equalizing a volumetric flow of the first air flow flowing out through said at least two first air outlet openings.
 13. The cab as claimed in claim 12, wherein the components are designed as ribs, baffles, guide walls, a housing, or duct sections having a changed cross-section. 